/// <summary>
/// Lowers structure store operations into distinct stores for each field.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
Store store)
{
var builder = context.Builder;
foreach (var(_, fieldAccess) in store.Value.Type as StructureType)
{
// Update target address
var address = builder.CreateLoadFieldAddress(
store.Location,
store.Target,
new FieldSpan(fieldAccess));
// Load the currently registered SSA value and store it
var value = context.GetValue(
context.Block,
new FieldRef(store.Value, fieldAccess));
var loweredStore = builder.CreateStore(
store.Location,
address,
value);
context.MarkConverted(loweredStore);
}
context.Remove(store);
}
/// <summary>
/// Lowers phi values.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData data,
PhiValue phi)
{
foreach (var(fieldType, fieldAccess) in phi.Type as StructureType)
{
// Build a new phi which might become dead in the future
var phiBuilder = context.Builder.CreatePhi(
phi.Location,
fieldType);
// Register the lowered phi
data.AddPhi(new LoweredPhi(
phi,
fieldAccess,
phiBuilder));
// Bind the new phi value
context.SetValue(
context.Block,
new FieldRef(phi, fieldAccess),
phiBuilder.PhiValue);
}
context.Remove(phi);
}
/// <summary>
/// Lowers get field operations into separate SSA values.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
GetField getField)
{
if (getField.Type is StructureType structureType)
{
foreach (var(_, fieldAccess) in structureType)
{
// Get the source value
var value = context.GetValue(
context.Block,
new FieldRef(
getField.ObjectValue,
new FieldSpan(
getField.FieldSpan.Index + fieldAccess.Index)));
// Bind the mapped SSA value
context.SetValue(
context.Block,
new FieldRef(getField, fieldAccess),
value);
}
context.Remove(getField);
}
else
{
var getFieldValue = context.GetValue(
context.Block,
new FieldRef(getField.ObjectValue, getField.FieldSpan));
context.ReplaceAndRemove(getField, getFieldValue);
}
}
/// <summary>
/// Converts a store node into an SSA value.
/// </summary>
private static void Convert(
SSARewriterContext <Value> context,
ConstructionData data,
Store store)
{
if (!data.TryGetConverted(store.Target, out var storeRef))
{
return;
}
Value ssaValue = store.Value;
if (!storeRef.IsDirect)
{
ssaValue = context.GetValue(context.Block, storeRef.Source);
ssaValue = context.Builder.CreateSetField(
store.Location,
ssaValue,
storeRef.FieldSpan,
store.Value);
}
context.SetValue(context.Block, storeRef.Source, ssaValue);
context.Remove(store);
}
/// <summary>
/// Lowers structure load operations into distinct loads for each field.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
Load load)
{
var builder = context.Builder;
foreach (var(_, fieldAccess) in load.Type as StructureType)
{
// Update source address
var address = builder.CreateLoadFieldAddress(
load.Location,
load.Source,
new FieldSpan(fieldAccess));
// Load value and store its reference in the current block
var loweredLoad = builder.CreateLoad(load.Location, address);
context.SetValue(
context.Block,
new FieldRef(load, fieldAccess),
loweredLoad);
context.MarkConverted(loweredLoad);
}
context.Remove(load);
}
/// <summary>
/// Converts a load node into an SSA value.
/// </summary>
private static void Convert <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
LoadElementAddress loadElementAddress)
where TConstructionData : IConstructionData
{
if (!data.TryGetConverted(loadElementAddress.Source, out var leaRef))
{
return;
}
// Get the primitive constant field offset
loadElementAddress.Assert(loadElementAddress.IsViewAccess);
var fieldOffset = loadElementAddress.Offset.ResolveAs <PrimitiveValue>();
loadElementAddress.AssertNotNull(fieldOffset);
// Map the field index + 1 to skip the initial array length
int fieldIndex = fieldOffset.Int32Value + 1;
data.AddConverted(
loadElementAddress,
leaRef.Access(new FieldAccess(fieldIndex)));
context.Remove(loadElementAddress);
}
/// <summary>
/// Converts an address-space cast into an SSA binding.
/// </summary>
private static void Convert(
SSARewriterContext <Value> context,
ConstructionData data,
AddressSpaceCast addressSpaceCast)
{
if (!data.TryGetConverted(addressSpaceCast.Value, out var castRef))
{
return;
}
data.AddConverted(addressSpaceCast, castRef);
context.Remove(addressSpaceCast);
}
/// <summary>
/// Converts a new view into an SSA value.
/// </summary>
private static void Convert <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
NewView newView)
where TConstructionData : IConstructionData
{
if (!data.TryGetConverted(newView.Pointer, out var newViewRef))
{
return;
}
data.AddConverted(newView, newViewRef);
context.Remove(newView);
}
/// <summary>
/// Converts an address-space cast into an SSA binding.
/// </summary>
protected static void Convert <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
AddressSpaceCast addressSpaceCast)
where TConstructionData : IConstructionData
{
if (!data.TryGetConverted(addressSpaceCast.Value, out var castRef))
{
return;
}
data.AddConverted(addressSpaceCast, castRef);
context.Remove(addressSpaceCast);
}
protected static void ConvertAlloca <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
Alloca alloca,
Value initValue)
where TConstructionData : IConstructionData
{
alloca.Assert(data.ContainsAlloca(alloca));
// Bind the init value and remove the allocation from the block
context.SetValue(context.Block, alloca, initValue);
data.AddConverted(alloca, new FieldRef(alloca));
context.Remove(alloca);
}
/// <summary>
/// Converts a field-address operation into an SSA binding.
/// </summary>
private static void Convert(
SSARewriterContext <Value> context,
ConstructionData data,
LoadFieldAddress loadFieldAddress)
{
if (!data.TryGetConverted(loadFieldAddress.Source, out var fieldRef))
{
return;
}
data.AddConverted(
loadFieldAddress,
fieldRef.Access(loadFieldAddress.FieldSpan));
context.Remove(loadFieldAddress);
}
/// <summary>
/// Converts a field-address operation into an SSA binding.
/// </summary>
protected static void Convert <TConstructionData>(
SSARewriterContext <Value> context,
TConstructionData data,
LoadFieldAddress loadFieldAddress)
where TConstructionData : IConstructionData
{
if (!data.TryGetConverted(loadFieldAddress.Source, out var fieldRef))
{
return;
}
data.AddConverted(
loadFieldAddress,
fieldRef.Access(loadFieldAddress.FieldSpan));
context.Remove(loadFieldAddress);
}
/// <summary>
/// Converts an alloca node to its initial SSA value.
/// </summary>
private static void Convert(
SSARewriterContext <Value> context,
ConstructionData data,
Alloca alloca)
{
if (!data.ContainsAlloca(alloca))
{
return;
}
var initValue = context.Builder.CreateNull(
alloca.Location,
alloca.AllocaType);
context.SetValue(context.Block, alloca, initValue);
data.AddConverted(alloca, new FieldRef(alloca));
context.Remove(alloca);
}
/// <summary>
/// Converts a load node into an SSA value.
/// </summary>
private static void Convert(
SSARewriterContext <Value> context,
ConstructionData data,
Load load)
{
if (data.TryGetConverted(load.Source, out var loadRef))
{
var ssaValue = context.GetValue(context.Block, loadRef.Source);
if (!loadRef.IsDirect)
{
ssaValue = context.Builder.CreateGetField(
load.Location,
ssaValue,
loadRef.FieldSpan);
}
context.ReplaceAndRemove(load, ssaValue);
}
else if (!load.Uses.HasAny)
{
context.Remove(load);
}
}
/// <summary>
/// Lowers set field operations into separate SSA values.
/// </summary>
private static void Lower(
SSARewriterContext <FieldRef> context,
LoweringData _,
SetField setField)
{
foreach (var(_, fieldAccess) in setField.Type as StructureType)
{
Value value;
if (setField.FieldSpan.Contains(fieldAccess))
{
// Get value from the source value
value = setField.Value;
if (value.Type is StructureType)
{
var getFieldAccess = fieldAccess.Subtract(
setField.FieldSpan.Index);
value = context.GetValue(
context.Block,
new FieldRef(value, getFieldAccess));
}
}
else
{
// Load the currently registered SSA value
value = context.GetValue(
context.Block,
new FieldRef(setField.ObjectValue, fieldAccess));
}
// Bind the mapped SSA value
context.SetValue(
context.Block,
new FieldRef(setField, fieldAccess),
value);
}
context.Remove(setField);
}